1. Field of the Invention
This invention relates to the treatment of domestic sewage sludge, garbage, animal manures and similar nitrogenous waste material and the scrubbing of stack gases. More particularly this invention relates to a unique composition essentially consisting of a salt of a lignosulphonic acid and a foaming surfactant system and the use thereof in treating nitrogenous wastes. When applied in the form of a dried powder or as a solution, it serves the multiple function of odor control, containment of evolved gases, stabilization of amines and the proteinaceous components and the reduction of associated populations of noxious insects. The lignosulphonic acid-salt surfactant composition need merely be applied to the surface or intimately mixed with the organic debris. Even subsequent drying or admixture with soil as an organic additive, does not overcome this most desirable odor-free characteristic that has been imparted.
2. Description of the Prior Art
Treatment and disposal of primary domestic sewage sludge is an ever increasing problem. Outright incineration is costly and a source of atmospheric pollution. Open air drying gives off large volumes of malodorous gases. Such drying also encourages development of dense fly populations. It also requires large land areas, which is obviously undesirable. Artificial rapid drying is costly and produces difficult to control malodorous stack gases. Scrubbing of stack gases may even be required by the environmental authorities. The resultant sludge may contain high concentrations of pathogenic bacteria (e.g. samonella, clostridia, staphlococci, and pathogenic protozoa). Such sludge can usually be applied to agricultural soils only under the most stringent conditions.
Compounding the aforementioned problems is the fact that there is a tremendous volume of animal waste generated daily in the United States. It currently amounts to over 2 billion tons annually. Its high biochemical oxygen demand and the nutrient materials and pathogens contained therein, makes it a serious source of water pollution if disposed of in land runoffs. Large scale poultry and cattle farming creates even greater problems especially when urban development encroaches upon farmland areas. The development of insects and malodors is intolerable as urban development supercedes farmland. Fish kills, eutrophication of lakes, nitrate contamination of aquifers, dusts and off-flavors of surface waters are frequently associated with such animal husbandry.